Helleborus plant named ‘COSEH 700’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘COSEH 700’, characterized by its upright and mounded plant habit; medium green-colored leaves; freely flowering habit; and large light green-colored flowers.

Botanical designation: Helleborus niger×Helleborus lividus.

Cultivar denomination: ‘COSEH 700’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Helleborus plant, botanically known as Helleborus niger×Helleborus lividus, and hereinafter referred to by the name ‘COSEH 700’.

The new Helleborus plant is a product of a planned breeding program in Glandorf, Germany. The objective of the breeding program was to create new uniform Helleborus cultivars with unique and attractive flower coloration and resistance to pests.

The new Helleborus plant originated from a cross-pollination conducted by the Inventor in Glandorf, Germany in January, 2003 of an unnamed proprietary seedling selection of Helleborus niger, not patented, as the female, or seed, parent with a proprietary selection of Helleborus lividus identified as code number 05-03, not patented, as the male, or seed, parent. The new Helleborus plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination grown in a controlled greenhouse environment in Glandorf, Germany in December, 2005.

Asexual reproduction of the new Helleborus plant by divisions in a controlled greenhouse environment in Glandorf, Germany since February, 2006, has shown that the unique features of this new Helleborus plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment and cultural practices such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘COSEH 700’. These characteristics in combination distinguish ‘COSEH 700’ as a new and distinct cultivar of Helleborus:

-   -   1. Upright and mounded plant habit.     -   2. Medium green-colored leaves.     -   3. Freely flowering habit.     -   4. Long flowering period.     -   5. Large light green-colored flowers.

Compared to plants of the parent selections, plants of the new Helleborus are more uniform and more freely flowering.

Plants of the new Helleborus can be compared to plants of Helleborus niger×Helleborus sternii ‘HGC Silvermoon’, disclosed in U.S. Plant Pat. No. 15,639. Plants of the new Helleborus differ primarily from plants of ‘HGC Silvermoon’ in the following characteristics:

-   -   1. Plants of the new Helleborus are not as vigorous as plants of         ‘HGC Silvermoon’.     -   2. Plants of the new Helleborus and ‘HGC Silvermoon’ differ in         leaf and flower color.

BRIEF DESCRIPTION OF THE PHOTOGRAPH

The accompanying colored photograph illustrates the overall appearance of the new Helleborus plant, showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photograph may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of the new Helleborus plant. The photograph comprises a side perspective view of a typical flowering plant of ‘COSEH 700’ grown in a container.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photograph and following observations, measurements and values describe plants grown in Glandorf, Germany in 15-cm containers during the winter in an outdoor nursery and under conditions which closely approximate commercial Helleborus production. During the production of the plants, day temperatures ranged from 5° C. to 32° C. and night temperatures ranged from 1° C. to 25° C. Plants had been growing for one year when the photograph and the description were taken. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2001 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus niger×Helleborus lividus ‘COSEH     700’. -   Parentage:     -   -   Female, or seed, parent.—Unnamed proprietary seedling             selection of Helleborus niger, not patented.         -   Male, or pollen, parent.—Proprietary selection of Helleborus             lividus identified as code number 05-03, not patented. -   Propagation:     -   -   Type.—By divisions.         -   Time to initiate roots.—About 56 days at 4° C. to 12° C.         -   Time to produce a rooted young plant.—About six months at             4° C. to 12° C.         -   Root description.—Thick to thin, fleshy; white to brown in             color.         -   Rooting habit.—Sparse. -   Plant description:     -   -   Plant form and growth habit.—Herbaceous perennial; upright             and mounded plant habit; moderately vigorous growth habit.         -   Plant height.—About 20 cm to 25 cm.         -   Plant diameter (area of spread).—About 25 cm to 35 cm. -   Foliage description:     -   -   Arrangement.—Palmately compound with three to five leaflets             per leaf.         -   Leaf length.—About 4 cm to 8 cm.         -   Leaf width.—About 2.5 cm to 5.5 cm.         -   Leaflet shape.—Roughly ovate.         -   Leaflet apex.—Acute.         -   Leaflet base.—Asymmetrically acute.         -   Leaflet margin.—Serrate.         -   Leaflet texture, upper and lower surfaces.—Smooth, glabrous;             leathery.         -   Leaflet venation pattern.—Pinnate; reticulate.         -   Leaflet color.—Developing leaves, upper surface: Close to             137A. Developing leaves, lower surface: Darker than 191A.             Fully developed leaves, upper surface: Darker than 147A;             venation, close to 146B. Fully developed leaves, lower             surface: Darker than 147B; venation, close to 166A.         -   Petiole.—Length: About 5 mm to 10 mm. Diameter: About 2 mm             to 4 mm. Texture, upper and lower surfaces: Smooth,             glabrous. Color, upper and lower surfaces: Close to 200A. -   Flower description:     -   -   Flower shape and habit.—Single rotate flowers; freely             flowering habit, about 30 to 40 flowers developing per             plant. Petals not observed.         -   Fragrance.—Moderately to strongly fragrant, pleasant.         -   Natural flowering season.—Long flowering period; plants             flower from December to March in Germany.         -   Flower longevity on the plant.—About three weeks; flowers             persistent.         -   Flower buds.—Length: About 1 cm to 2 cm. Diameter: About 8             mm to 12 mm. Shape: Ovoid. Color: Close to 145C; towards the             base, overlain with close to 183D.         -   Flowers.—Diameter: About 7 cm to 8 cm. Depth (height): About             2 cm to 3 cm.         -   Sepals.—Arrangement: About five in a single whorl. Length:             About 3.5 cm to 4 cm. Width: About 3.5 cm to 4 cm. Shape:             Broadly ovate to rounded. Apex: Rounded. Base: Obtuse.             Margin: Entire. Texture, upper and lower surfaces: Smooth,             glabrous; satiny. Color: When opening, upper surface: Close             to 145C; towards the margins, close to 145D. When opening,             lower surface: Close to 145D. Fully opened, upper surface:             Close to 145B; color becoming closer to between 138B and             139D with development. Fully opened, lower surface: Between             157B and 145C; towards the base, overlain with close to             183B.         -   Peduncles.—Strength: Strong. Length: About 20 cm. Diameter:             About 5 mm to 10 mm. Aspect: Mostly upright. Texture:             Smooth, glabrous. Color: Close to 145C; towards the base,             overlain with close to 183D.         -   Reproductive organs.—Stamens: Quantity per flower:             About 100. Anther shape: Elliptical. Anther length: About 1             mm to 2 mm. Anther color: Close to 7B. Pollen amount: None             observed.         -   Pistils.—Quantity per flower: About five. Pistil length:             About 1.5 cm. Stigma shape: Pointed. Stigma color: Close to             150D. Style length: About 8 mm. Style color: Close to 150D.             Ovary color: Close to 150D. Nectaries: Quantity per flower:             About 13. Length: About 1 cm. Shape: Salverform. Color:             Towards the base, close to 145A; towards the apex, close to             2B. Seeds/fruits: Seed and fruit development have not been             observed. -   Garden performance: Plants of the new Helleborus have been observed     to have good garden performance and to tolerate rain, wind and     temperatures from about—10° C. to about 36° C. -   Pathogen/pest resistance: Plants of the new Helleborus have not been     shown to be resistant to pathogens and pests common to Helleborus. 

1. A new and distinct Helleborus plant named ‘COSEH 700’ as illustrated and described. 